Part 18 (1/2)

The word _sequence_ is also applied to a succession of similar melodic progressions, as in Fig. 73.

[Ill.u.s.tration: Fig. 73.]

209. _Modulation_ is a change of key without any break in the continuity of chords or melody tones. _Harmonic modulations_ are usually effected through the medium of a chord, some or all of whose tones are common to both keys. Examples of both _harmonic_ and _melodic modulations_ are shown in Figs. 74 and 75.

[Ill.u.s.tration: Fig. 74.]

The chord most frequently used in modulating is the _dominant seventh_, _i.e._, a seventh chord (see Sec. 201) on the dominant tone of the key.

In the key of C this chord is G--B--D--F; in the key of D it is A--C[sharp]--E--G; in the key of A[flat] it is E[flat]--G--B[flat]--D[flat], etc.

[Ill.u.s.tration: Fig. 75.]

210. A _suspension_ is the temporary subst.i.tution of a tone a degree higher than the regular chord-tone, this temporary tone being later replaced by the regular chord-tone. See Fig. 76 (_a_).

[Ill.u.s.tration: Fig. 76.]

211. A _r.e.t.a.r.dation_ is the temporary subst.i.tution of a tone a degree lower than the regular tone, this tone (as in the case of the suspension) being later replaced by the regular chord tone. See Fig. 77 (_a_).

[Ill.u.s.tration: Fig. 77.]

The ”regular chord tone” to which both suspension and r.e.t.a.r.dation resolve is called the _tone of resolution_.

212. The _antic.i.p.ation_ is a chord-tone introduced just before the rest of the chord to which it belongs is sounded. See Fig. 78 (_a_).

[Ill.u.s.tration: Fig. 78.]

213. A _pedal point_ (or _organ point_) is a tone sustained through a succession of harmonic progressions, to the chords of some of which it usually belongs. The term _pedal point_ originated in organ playing, (where the foot on a pedal can sustain a tone while the hands are playing a succession of harmonies), but as now used it may be applied to any kind of music. The dominant and tonic are the tones most often used in this way. See Fig. 79.

[Ill.u.s.tration: Fig. 79. SCHUMANN]

214. When the upper three voices of a four-voice composition are written close together (the soprano and tenor never appearing more than an octave apart), the term _close position_ is applied. But when the upper voices are not written close together, the term _open position_ is applied.

215. By _transposition_ is meant playing, singing, or writing a piece of music in some other key than the original. Thus _e.g._, if a song written in the key of G is too high in range for a soloist, the accompanist sometimes _transposes_ it to a lower key (as F or E), thus causing all tones to sound a second or a third lower than they did when the same song was played in the original key.

CHAPTER XIX

MISCELLANEOUS TERMS

_A battuta_--with the beat; in strict rhythm. [Transcriber's Note: Corrected error ”battua” in original.]

_a quatre mains_--for four hands.

_Accompagnamento_--the accompaniment.

_All'unisono_--in unison.

_Alla breve_--2/2 measure.